メソッド

▼引数　実行

public static void main(String[] args){
	test(10);
}
public static void test(int num){
	int ans = num * 2;
	System.out.println(ans);
}

▼戻り値　実行

public static void main(String[] args){
	int num = test();
	System.out.println(num);
}
public static void test(){
	int num = 10;
	return num;
}

▼引数・戻り値　実行

public static void main(String[] args){
	int num = 10;
	int ans = test(num);
	System.out.println(ans);
}
public static void test(int num){
	num = num * 2;
	return num;
}